Subversion locks can be broken by anyone with write access to the particular
project. The only way to "tightfist" that is to do it socially, or somehow
write in some procedure that only allows certain people to do it.

Are you referring to the social issue, or the software issue?

Now, one big problem of locks is that as the programmer without the lock
makes changes and test setups, they can't enter them in source control. That
becomes a complete violation of source control, and can lead to lost work.
(But you know that!)

This is why subversion has branches, and the ability to merge among them:
why aren't your authors using them?